Reducing the permeability of carbon or graphite objects - by impregnation with a suspension of colloidal graphite

摘要

The permeability of a carbon object is reduced by using a min. pressure of 1.014 atmos. to impregnate the object with a liq. suspension contg. (by wt) na) 95-99.9% of a (non)polar liq. with freezing point below room temp.; and (b) 0.01-5 % fine carbonaceous particles. The prod. is used e.g. for the impregnation of graphite reaction vessels and pipes used in the chemical and metallurgical industries. Graphite is an excellent material for such uses but is disadvantage is its porosity. The process requires neither high temps. nor pressures to impregnate the object. Impregnation can be achieved using an aq. suspension e.g. of colloidal graphite, at room temp., forced into the pores of the graphite by compressed air.